Engine Idling Rough after Sea Foam

I agree. Hard to say. It’ll blow smoke whether carbon is present or not, I think, if you use it basically as a fuel at or near idle.

Not necessarily. I’ve got two vehicles that run great with no check engine lights, have never been “Seafoamed”, and have over 180k. I’m not for or against Seafoam decarboning. But if it runs good before and runs good after with no CEL, and all you’ve got to show for it is some smoke…Meh.

I’ve used it to free stuck lifters, though. But I wonder how much carbon buildup (in the combustion chamber) is an issue, under normal driving.

I’m confused. Topic is labeled as an F150. Where does DPF come in?

Ford Makes the F150.

Don’t they?


They do indeed. I’m not certain a 2006 has a DPF, though.

DPF, in my mind, is a desiel particulate filter. No deisel option on an F150 in 2006. What am I missing?


Differential Pressure Feedback Electronic, for the EGR system.

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Delta Pressure Feedback EGR’

Tester :roll_eyes:

Yeah. :roll_eyes:. You’re right, and you’re the expert. But no one on earth that isn’t a paid mechanic understands DPF as delta pressure feedback. So roll them eyes elsewhere.

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That DPFE sensor was the subject of quite a few posts here in Ford cars of that era, don’t recall if there were posts about it for Ford trucks though. OP can use the forum search feature, see what other’s have said. My older Ford truck doesn’t use a DPFE, but from the look of Tester’s diagram above, the DPFE output signal measures the amount of exhaust flow through the EGR valve. Monitored by the ECM, which turns on the CEL if the flow doesn’t match what is anticipated for the driving condition. On my Corolla that function is done by a thermistor in the EGR, which heats up more with increasing exhaust flow.

DPFE Ford posts seem to have decreased dramatically here, whatever the problem, must have been corrected.

That’s right Scrapy!

I hate when you have enlighten someone who argues with you who’s not a mechanic. :roll_eyes:


Well, you found out otherwise!

Yes, sir. I am not a mechanic, and I will freely admit that. I’m just trying to help a guy out with the admittedly limited knowledge I have. I do not see where I “argued” with your professionalism. Hence, I said this:

Where does DPF come in?

DPF, in my mind, is a desiel particulate filter. No deisel option on an F150 in 2006. What am I missing?

‘‘Twas a question.

I also said this:

I think that stuff got recirculated back into the intake. You’re truck ingested some lube, and set the check engine light. You probably burned it off by now and are good to go.

As I understand it, (note I’m not a professional mechanic), lube getting redirected into the intake (recirculation) might cause a misfire. If I’m incorrect, then…reply to that. Being condescending with the eye rolling isn’t helpful. If I’m wrong, feel free to correct me at any time. The eye rolling, you can…do something else with that.

Worked pretty well for me. I had an old carb’d Mitsubishi from the 80’s. Had enough carbon buildup that it would diesel after you shut it off. And not for just a few cycles either - it’d just keep going until you put it in gear and let the clutch out to put a load on the engine. I Seafoamed it and the dieseling disappeared.

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Some people say carbon on the piston top reaches equilibrium after a while so don’t worry about it. Carbon buildup on valves is another matter.

Have you checked your fuel trims? I use Forscan (only works with Ford vehicles).

Note, I am note a professional mechanic. I have read that carbon buildup on valves isn’t generally an issue on port injection cars. I could be mistaken. I am not a professional mechanic.

No, I haven’t. I’m not a professional mechanic :grin:. I assumed if they were out of whack I’d get some sort of check engine light and corresponding code.

I’ve used Seafoam before, I’ve even put it through the intake of a vehicle or two. I don’t have any issue with Seafoam, and if someone is trying to correct a problem, I think it’s a good product. When I say I think the decarbonization aspect of it is a little overblown, I’m referring to some of the guys on YouTube that have a vehicle with no real issues, then do the Seafoam injection smoke show, and say it runs “better”. I think a little of that might be a placebo affect. I didn’t notice any improvement when I used it, but I really didn’t have an engine issue to begin with.

Just figured I’d try it. It made a lot of smoke. Sort of like that time in high school with those hand rolled cigarettes that girl had. :stuck_out_tongue_closed_eyes:


“I don’t have any issue with Seafoam, and if someone is trying to correct a problem, I think it’s a good product”

The intake breathes crankcase vapor via PCV and exhaust via EGR. Port injection helps but deposits can still occur.

Fuel trim numbers have a wide range before setting a code. Before that happens you can still lose performance and waste fuel. The numbers provide early warning of problems. Vacuum leaks, EVAP system, O2 sensors, EGR, PCV, etc.

The numbers can be positive or negative. 0 is ideal. Not likely with an older car though. Some people say under 10 don’t worry about it.

I like 5 or better.

Carbon on piston domes can cause hot spots which may lead to ignition knock, which is not a good thing.

I think the reference is to what Ford calls the DPFE device (sensor), part of their EGR system. The “D” doesn’t stand for diesel, stands for “differential” or “delta”. For more info, look at the diagram in Tester’s post above, number 19.

DIY’ers who work mainly on their own cars don’t know everything that the pro’s know. Not even close. And not in dispute. That difference is part of what makes the forums interesting and informative.

I don’t know whether it has been established yet that the DPFE sensor is used on Ford trucks.